Liquid crystal display (LCD) technology is currently the most widely used display technology and mainly applied in TVs, mobile phones and public information display devices. In an LCD device, the color of transmitted light is changed by utilization of different refraction angles by the control of the deflection angle of liquid crystal molecules. In the LCD device, an electric field is changed by the change of voltage on an array substrate, so that the deflection direction of the liquid crystal molecules is controlled, and hence the liquid crystal molecules reveal different light-shielding properties and light-transmitting properties at different angles. On the basis of the principle, a required image may be formed by the control of each pixel unit.